1. Field of the Invention
The present invention concerns a method for checking and monitoring the friction between the traction sheave and the suspension ropes of an elevator, whereby the slippage between the traction sheave and the suspension ropes is measured, the elevator comprising the elevator machine, the hoistway and the elevator car and counterweight moving in the hoistway.
2. Description of Related Prior Art
The safety of a traction sheave elevator depends, among other things, on whether the friction between the traction sheave and the suspension ropes is sufficient. As is known, the friction is dependent on many factors and subject to change in the course of time. Among such factors are wear of the rope groove, reduction of the rope diameter, changes in the lubrication conditions and tolerances in connection with change of ropes and machining of the grooves. A reduced friction may involve risks regardless of whether the safety gear of the elevator is designed to operate during downward movement or both downward and upward movement.